Temperature-dependent structural change of D-penicillamine-capped chiral gold nanoparticles investigated by infrared spectroscopy.

The structure and stability of D-penicillamine-capped gold nanoparticles (d-Pen Au NPs) were studied using spectroscopic tools. The synthesis of d-Pen Au NPs was examined using high-resolution transmission electron microscopy (HR-TEM), UV-vis absorption spectroscopy, and circular dichroism (CD). Temperature-dependent reversible structural changes of d-Pen Au NPs were observed using infrared spectroscopic tools.

Label-free Raman spectroscopy for accessing intracellular anticancer drug release on gold nanoparticles.

We investigated glutathione (GSH)-induced purine or pyrimidine anticancer drug release on gold nanoparticle (AuNP) surfaces by means of label-free Raman spectroscopy. GSH-triggered releases of 6-thioguanine (6TG), gemcitabine (GEM), acycloguanosine (ACY), and fadrozole (FAD) were examined in a comparative way by means of surface-enhanced Raman scattering (SERS). The GSH-induced dissociation constant of GEM (or ACY/FAD) from AuNPs was estimated to be larger by more than 38 times than that of 6TG from the kinetic relationship.

Confocal Raman microspectroscopic study of folate receptor-targeted delivery of 6-mercaptopurine-embedded gold nanoparticles in a single cell.

We investigate the cellular uptake behaviors and efficacy of folate-coated gold nanoparticles (AuNPs) for the targeted drug delivery system in human cancer cells. Folate-conjugated AuNPs embedded with a purine analogue cancer drug of 6-mercaptopurine (6MP) were assembled via a 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) coupling reaction between the amino group of 4-aminobenzenethiol (ABT) and the carboxyl group of folic acid. The assembly of folate and 6MP on AuNPs has been examined by absorption spectroscopy, transmission electron microscopy (TEM), and confocal Raman spectroscopy.

In vitro toxicity of serum protein-adsorbed citrate-reduced gold nanoparticles in human lung adenocarcinoma cells.

We examined the cytotoxicity effect of the serum protein coated gold nanoparticles (AuNPs) in the A549 cells. Negatively charged AuNPs were prepared by chemical reduction using citrate. The dimension and surface charge of AuNPs were characterized using transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential measurements.

Preferential adsorption of fetal bovine serum on bare and aromatic thiol-functionalized gold surfaces in cell culture media.

Intracellular uptake of serum-coated gold nanoparticles (AuNPs) in a single mammalian cell was examined in order to investigate the interactions of cell culture media and aromatic thiol-functionalized gold surfaces using micro-spectroscopic tools. The AuNPs modified by the aromatic thiols of para-aminobenzenethiol (ABT), para-hydroxy benzenethiol (HBT), and para-carboxylic benzenethiol (CBT, para-mercaptobenzoic acid) bearing NH(2), OH, and COOH surface functional groups are presumed to adsorb the serum proteins as indicated from the compiled quartz crystal microbalance (QCM) data. The QCM results indicate that among the constituents, fetal bovine serum (FBS) should be the major adsorbate species on AuNPs incubated in Roswell Park Memorial Institute (RPMI) medium.